The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Diesel engines typically produce torque more efficiently than gasoline engines. This increase in efficiency may be due to an increased compression ratio and/or the combustion of diesel fuel, which has a higher energy density than that of gasoline. The combustion of diesel fuel produces particulate. The particulate is filtered from exhaust by a diesel particulate filter (DPF). Other engine systems may also include a particulate matter (PM) filter. With time, the PM filter may fill with particulate and restrict the flow of the exhaust. The particulate is combusted through a process referred to as regeneration.
Regeneration may be accomplished via heat provided by, for example, combustion of the diesel fuel, a catalyst located upstream of the PM filter, and/or a heater that is associated with the PM filter. For example, fuel may be injected into the exhaust stream. One or more catalysts may be disposed in the exhaust stream and may combust the injected fuel. The combustion of the fuel by the catalysts generates heat, thereby increasing the temperature of the exhaust. The increased temperature of the exhaust combusts the particulate trapped in the PM filter.